This invention relates to tilt and range measurement of a target surface for determining, for example, x, y, z, pitch, yaw and/or roll of a two-dimensional scale surface.
Precision measuring systems are employed in a wide variety of fields. Many industrial systems and devices employ precision measuring systems for accurately positioning and orienting mechanical components. For example, machine tools, robots, printers, and multi-function devices employ precision measuring systems to accurately position and orient mechanical components.
Seung-Woo Kim et al. disclose a two-point diffraction interferometer for absolute distance measurement including tilt angle information in “Two-point Diffraction Interferometer for Absolute Distance Measurement,” Interferometry XII: Techniques and Analysis, Proceedings of SPIE Vol. 5531 (SPIE, Bellingham, Wash., 2004). The two-point diffraction interferometer employs the spherical wavefronts that are output from the ends of two single mode fibers (SMF) that are split from a single laser source to generate an interference field or interference pattern throughout a measurement space. The interference pattern is detected directly on a detector array, which forms a sensor. Distance measurements between the fiber ends and the sensor along the X, Y and Z axes, as well as pitch, roll and/or yaw orientation of the detector array in the interference field, may be determined based on data detected by the detector array.